﻿Shader "Unlit/AlphaBlend"
{
	Properties
	{
		_MainTex ("Texture", 2D) = "white" {}
		_Color ("Color", Color) = (1, 1, 1, 1)
		_AlphaScale ("Alpha Scale", Range(0, 1)) = 1
	}
	SubShader
	{
		Tags {"Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent"}

		Pass
		{
			Tags {"LightMode" = "ForwardBase"}
			ZWrite Off
			Blend SrcAlpha OneMinusSrcAlpha
			CGPROGRAM
			#pragma mlti_compile_fwdbase
			#pragma vertex vert
			#pragma fragment frag
			#include "Lighting.cginc"
			
			sampler2D _MainTex;
			float4 _Color;
			float4 _MainTex_ST;
			float _AlphaScale;

			struct a2v 
			{
				float4 vertex : POSITION;
				float3 normal : NORMAL;
				float4 texcoord : TEXCOORD0;
			};

			struct v2f
			{
				float4 pos : SV_POSITION;
				float3 worldPos : TEXCOORD0;
				float3 worldNormal : TEXCOORD1;
				float2 uv : TEXCOORD2;
			};

			v2f vert(a2v v)
			{
				v2f o;
				o.pos = UnityObjectToClipPos(v.vertex);
				o.worldPos = mul(unity_ObjectToWorld, v.vertex);
				o.worldNormal = UnityObjectToWorldNormal(v.normal).xyz;
				o.uv = v.texcoord;
				return o;
			}

			fixed4 frag(v2f i) : SV_Target
			{
				fixed3 worldNormal = normalize(i.worldNormal);
				fixed3 worldLightDir = normalize(UnityWorldSpaceLightDir(i.worldPos));
				fixed4 texColor = tex2D(_MainTex, i.uv);
				fixed3 albedo = texColor.rgb * _Color.rgb;
				fixed3 diffuse = _LightColor0.rgb * albedo * max(0, dot(worldNormal, worldLightDir));
				fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz;
				return fixed4 (ambient + diffuse, texColor.a * _AlphaScale);
			}
			ENDCG
		}
		Pass
		{
			Tags {"LightMode" = "ForwardAdd"}
			ZWrite Off
			Blend SrcAlpha OneMinusSrcAlpha
			CGPROGRAM
			#pragma mlti_compile_fwdadd
			#pragma vertex vert
			#pragma fragment frag
			#include "Lighting.cginc"
			#include "AutoLight.cginc"
			
			sampler2D _MainTex;
			float4 _Color;
			float4 _MainTex_ST;
			float _AlphaScale;

			struct a2v 
			{
				float4 vertex : POSITION;
				float3 normal : NORMAL;
				float4 texcoord : TEXCOORD0;
			};

			struct v2f
			{
				float4 pos : SV_POSITION;
				float3 worldPos : TEXCOORD0;
				float3 worldNormal : TEXCOORD1;
				float2 uv : TEXCOORD2;
			};

			v2f vert(a2v v)
			{
				v2f o;
				o.pos = UnityObjectToClipPos(v.vertex);
				o.worldPos = mul(unity_ObjectToWorld, v.vertex);
				o.worldNormal = UnityObjectToWorldNormal(v.normal).xyz;
				o.uv = v.texcoord;
				return o;
			}

			fixed4 frag(v2f i) : SV_Target
			{
				fixed3 worldNormal = normalize(i.worldNormal);
				#ifdef USING_DIRECTIONAL_LIGHT
					fixed3 worldLightDir = normalize(_WorldSpaceLightPos0.xyz);
				#else
					fixed3 worldLightDir = normalize(_WorldSpaceLightPos0.xyz - i.worldPos.xyz);
				#endif
				UNITY_LIGHT_ATTENUATION(atten, i, i.worldPos);
				fixed4 texColor = tex2D(_MainTex, i.uv);
				fixed3 albedo = texColor.rgb * _Color.rgb;
				fixed3 diffuse = _LightColor0.rgb * albedo * max(0, dot(worldNormal, worldLightDir));
				fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz;
				return fixed4 ((ambient + diffuse) * atten, texColor.a * _AlphaScale);
			}
			ENDCG
		}
	}
	FallBack"Diffuse"
}
